From the author of

How Much of Your Life Is on the Internet?

Today, half of 80 million American adults have purchased something online,
and 8 million of those individuals use Amazon.com, which usually will store
buyer preferences. Most of us don't think about the transaction histories and
user preferences that are more frequently being mined, creating "personalized
pages" and direct email offers announcing products and services that "individuals
like us" are exploring.

But security on the Internet, vis-à-vis Web commerce, is only the tip
of the iceberg. Many security-conscious organizations, starting with the Electronic
Frontier Foundation (EFF), then TRUSTe, have been proponents of voluntary restrictions
on information collection, storage, and redistribution. The EFF, founded by
Lotus founder Mitch Kapor, saw a time when merging of data from computer databases,
public government records, retail purchases, medical records, and the "data
wake" left by our Web surfing could create a fairly accurate representation
of our persona. By using common key fields, creating this master file would
not be too difficult.